If z=eiθz = e^{i\theta}z=eiθ, evaluate the real part of 11−z\frac{1}{1-z}1−z1 in terms of θ\thetaθ.
12\frac{1}{2}21
cos(θ)\cos(\theta)cos(θ)
000
−12-\frac{1}{2}−21